def symmetrize_compact_force_constants(force_constants, primitive, level=1):
"""Symmetry force constants by translational and permutation symmetries.
Parameters
----------
force_constants: ndarray
Compact force constants. Symmetrized force constants are overwritten.
dtype=double
shape=(n_patom,n_satom,3,3)
primitive: Primitive
Primitive cell
level: int
Controls the number of times the following steps repeated:
1) Subtract drift force constants along row and column
2) Average fc and fc.T
"""
s2p_map = primitive.s2p_map
p2s_map = primitive.p2s_map
p2p_map = primitive.p2p_map
permutations = primitive.atomic_permutations
s2pp_map, nsym_list = get_nsym_list_and_s2pp(s2p_map, p2p_map,
permutations)
try:
import phonopy._phonopy as phonoc
phonoc.perm_trans_symmetrize_compact_fc(force_constants, permutations,
s2pp_map, p2s_map, nsym_list,
level)
except ImportError:
text = ("Import error at phonoc.perm_trans_symmetrize_compact_fc. "
"Corresponding pytono code is not implemented.")
raise RuntimeError(text)
def symmetrize_compact_force_constants(force_constants,
supercell,
primitive,
level=2):
"""Symmetry force constants by translational and permutation symmetries.
Here force constants are stored in a compact form:
(n_patom, n_satom, 3, 3).
For the symmetrization, permutation array is necessary.
level controls the number of times the following steps repeated:
1) transpose fc
2) subtract drift-fc/n_satom from fc elements
where fc is overwritten.
"""
s2p_map = primitive.get_supercell_to_primitive_map()
p2s_map = primitive.get_primitive_to_supercell_map()
p2p_map = primitive.get_primitive_to_primitive_map()
permutations = primitive.get_atomic_permutations()
s2pp_map, nsym_list = get_nsym_list_and_s2pp(s2p_map, p2p_map,
permutations)
try:
import phonopy._phonopy as phonoc
phonoc.perm_trans_symmetrize_compact_fc(force_constants, permutations,
s2pp_map, p2s_map, nsym_list,
level)
except ImportError:
print("Import error at phonoc.perm_trans_symmetrize_compact_fc.")
print("Corresponding pytono code is not implemented.")
import sys
sys.exit(1)
def symmetrize_compact_force_constants(force_constants,
supercell,
symmetry,
s2p_map,
p2s_map):
"""Symmetry force constants by translational and permutation symmetries.
Here force constants are stored in a compact form:
(n_patom, n_satom, 3, 3).
For the symmetrization, permutation array is necessary.
"""
rotations = []
trans = []
identity = np.eye(3, dtype='intc')
for r, t in zip(symmetry.get_symmetry_operations()['rotations'],
symmetry.get_symmetry_operations()['translations']):
if (r == identity).all():
rotations.append(r)
trans.append(t)
permutations = _compute_all_sg_permutations(
supercell.get_scaled_positions(),
np.array(rotations, dtype='intc', order='C'),
np.array(trans, dtype='double'),
np.array(supercell.get_cell().T, dtype='double', order='C'),
symmetry.get_symmetry_tolerance())
try:
import phonopy._phonopy as phonoc
phonoc.perm_trans_symmetrize_compact_fc(force_constants,
permutations,
s2p_map,
p2s_map)
except ImportError:
print("Import error at phonoc.perm_trans_symmetrize_compact_fc.")
print("Corresponding pytono code is not implemented.")
import sys
sys.exit(1)